The invention relates to the field of vanes for turbine engine.
Vanes from the prior art are known, comprising a main body and a metallic reinforcement on their leading edge or their trailing edge designed to protect the main body during impact by a foreign body such as a bird taken in by the turbine engine.
In reference to FIG. 1A, a vane A fitted with a metallic reinforcement R in the form of a foil covering the main body CP of the vane in the vicinity of the leading edge BA of the vane A has already been proposed in patent application FR 2 732 406 A1. The foil R has a profile (illustrated in FIGS. 1B and 1C) comprising a central part in the vicinity of the leading edge BA, and two opposite protrusions of material extending from the central part, on either side of the main body CP.
But such a foil has a number of drawbacks. A reinforcement of foil type is not very rigid; it is therefore likely to undergo pinching or wrinkling during its assembly with the main body CP of the vane A. The assembly is also made complex because of the fine thickness of the two abovementioned protrusions of material.
Also, the foil can, in use, be subject to tearing at the level of the leading edge. The foil also has an embrittlement zone F whereof the profile has a radius which depends on the preferred thickness of the vane. As a consequence, the foil R is not indicated to be connected to a main vane body of fine thickness as its embrittlement zone F has a profile of minimal radius; such a vane, after assembly of the reinforcement R, has a high risk of cracking following impact by a foreign body on the reinforcement.
A metal structural reinforcement connected to a main vane body made of composite material has also been proposed in patent application EP 1 908 919 A1, the profile of the reinforcement having a central part, and two opposite protrusions of material extending from the central part and defining a cavity wherein an end of the main body is housed. Arranged between the cavity and the leading edge is an additional recess designed to absorb some of the energy resulting from impact by a foreign body on the leading edge of the vane.
However, such a structural reinforcement is not entirely satisfactory, as the cavity defined between the protrusions of material and the recess extending this cavity necessarily give this reinforcement a minimal radius profile, if the main vane body to which this reinforcement is intended to be connected has minimal thickness.
To obtain a reinforcement having a larger radius profile, one solution could be to increase the length of the central part of the reinforcement between the leading edge and the main body. However, more material would have to be used or, as the reinforcement is metallic, the mass of the vane will be greater.